Browse Prior Art Database

Original Publication Date: 1990-Jun-30
Included in the Prior Art Database: 2004-Apr-05

Publishing Venue

Xerox Disclosure Journal


Toner is dispensed from a cartridge into a small drop area in the dispenser pipeline to be metered away by a dispense auger to the developer housing. A toner sensor is present in the drop area to detect the presence or absence of toner and is located in such that toner is fed to the sensor and at the same time augered away from it. When the toner cartridge is empty, the sensor no Ionger sees the presence of toner and signals the 'Replace Toner Cartridge'condition and brings the machine to a hard stop. The operator can rectify the situation only by inserting a fresh Cartridge. Under certain temperature and humidity conditions, toner bridges may be formed in front of the sensor face, which prevent the toner from reaching the sensor face. The toner could well bypass the area immediately in front of the sensor and feed directly to the dispense auger. The void formed in front of the sensor will erroneously translate into a false 'Replace Toner Cartridge' condition in spite of the fact that the Cartridge is full. This condition may last long enough and repeat enough times that the operator is forced to initiate a service call. The Figures illustrate a device for solving this problem. A flat stainless steel spring 14 cut to the shape as depicted in Figure 1 is insert molded to plastic mount 16 which has ramps that rigidly lock into detents that are molded in the dispenser pipeline. The rigid mounting of the spring to the dispenser pipeline is important to its function. Also, the dimensions of the mount are such that the flat stainless steel spring presents a slender profile in the dispenser auger tube 10 as depicted in Figure 2. The spring presents a slender profile to the toner flow path that enables it to break toner clumps and bridges in congested areas such as dispenser pipelines. When the dispenser auger 12 turns, it drives the protrusion or tang 20 (on the spring), whose dimensions are such that it causes the spring to be deflected to no more than one half the diameter to the dispenser tube.